<!DOCTYPE html>
<html >
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>背景色</title>
    <style>
        .box{
            width: 600px;
            height: 600px;
            background-color: wheat;
        }
        .child{
            width: 200px;
            height: 200px;
            background-color: rgba(250, 59, 12,0.3);
        }
        .child2{
            width: 200px;
            height: 200px;
            background: linear-gradient(to left,red,white,blue);
        }
    </style>
</head>
<body>
    <div class="box">
        <span> 你好</span>
        <div class="child">
            <span>我好</span>
        </div>
        <div class="child2">

        </div>
    </div>
</body>
</html>